Since lymphocyte responsiveness within the blastogenesis system is primarily a memory dependent effect and is not dependent upon the presence of specific antibody it was felt that this in vitro assay of cellular immunity might be a sensitive indicator of prior exposure to viral infection and could be utilized as a method of determining susceptibility to specific viral disease. Because of the importance of the herpes viruses as a source of recurrent disease in man and because of their association with the oncogenic state, the characteristics of human lymphocyte responsiveness to these viruses were studied. BIBLIOGRAPHIC REFERENCES: Ruckdeschel, J.C., Schimpff, S.C., Smyth, A.C., and Mardiney, M.R., Jr.: Herpes Zoster and Impaired Cell-Associated Immunity to the Varicella-Zoster Virus in Patients with Hodgkin's Disease. Amer. J. Med. 62: 77-85, 1977. Mardiney, M.R., Jr., and Ruckdeschel, J.C.: Discussion - Inhibition of in Vitro Lymphocyte Responsiveness by Measles Virus Antigen. Cell. Immunol. 28: 229, 1977.